The present invention relates to a process for converting conjugated diolefins and mixtures thereof to ethers. More particularly, the present invention comprises the process of reacting the conjugated diolefin with an aliphatic hydroxyl compound in the presence of a chelating phosphine adduct of zero valent nickel.
In Japanese Kokai No. 79/3,424, butadiene and ethylene glycol were reacted in the presence of bis(tri(o-tolyl)phosphine)palladium to prepare primarily ethylene glycol mono(2,7-octadienyl) ether and ethylene glycol di(2,7-octadienyl) ether. The catalyst was separated from the reaction mixture by super critical extraction employing ethane solvent.
In prior art processes, detrimental polymerization of alkadiene reactants, if present, cannot be avoided. Therefore, the principal products in the above reference process are not adducts of the alkadiene and the hydroxyl compound, but rather they comprise reaction products of oligomerized olefin and the hydroxyl compound.
It would be desirable to provide a process that allows the conversion of conjugated alkadienes to ethers. It would be further desirable to provide a process that allows the conversion of conjugated alkadienes to ethers while avoiding polymerization of the conjugated alkadiene. Finally, it would be desirable to provide a process for the preparation of novel unsaturated ethers having utility as solvents and cross-linking agents in polymer systems.